• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >A finite difference method for studying thermal deformation in two-dimensional micro scale metal thin films exposed to ultrashort pulsed lasers.
【24h】

A finite difference method for studying thermal deformation in two-dimensional micro scale metal thin films exposed to ultrashort pulsed lasers.

机译：一种研究超短脉冲激光暴露的二维微尺度金属薄膜热变形的有限差分方法。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Ultrashort-pulsed lasers have been attracting worldwide interest in science and engineering because the lasers with pulse durations on the order of sub-picoseconds to femtoseconds possess capabilities in limiting the undesirable spread of the thermal process zone in a heated sample during material processing at the microscale. Prevention of thermal damage is an important factor for success of ultrashort-pulsed lasers in real applications. The thermal damage induced by ultrashort pulses is intrinsically different from that induced by long-pulse or continuous lasers. It occurs after the heating pulse is over and involves the shattering of thin metal layers (without a clear signature of thermal damage by excessive temperature) rather than the melt damage caused by high temperatures. In this dissertation, by replacing the displacement components in the dynamic equations of motion using the velocity components, and employing a staggered grid, we develop a finite difference method for studying thermal deformation in two-dimensional films exposed to ultrashort-pulsed lasers, where the thin films are a single-layered thin film and a double-layered thin film with perfectly interfacial thermal contact and imperfectly interfacial thermal contact, respectively. The method is obtained based on the parabolic two-step heat transport equations. It accounts for the coupling effect between lattice temperature and strain rate, as well as for the hot electron blast effect in momentum transfer. The developed methodology allows us to avoid non-physical oscillations in the solution.; Such oscillations have been an intrinsic feature of most numerical method proposed so far in the context of problem of interest. The development of physical-based, numerical-oscillation-free methods for thermal analysis of thin metal films subjected to heating of ultrashort-pulsed lasers represents challenging tools at the forefront of this practically important area of research.; This method is tested for its applicability by investigating the temperature rise and deformation in (1) a single-layered gold thin film, (2) a double-layered gold and chromium thin film with perfect thermal contact at the interface, and (3) a double-layered gold and chromium thin film with imperfect thermal contact at the interface. Results show that there are no non-physical oscillations in the solutions, and the method is promising.
机译：超短脉冲激光器一直在全世界引起科学和工程学的兴趣，因为脉冲持续时间在亚皮秒级至飞秒级数量级的激光器具有在微米级材料加工过程中限制加热样品中热处理区不良扩散的能力。 。防止热损坏是超短脉冲激光器在实际应用中成功的重要因素。超短脉冲引起的热损伤本质上不同于长脉冲或连续激光引起的热损伤。它是在加热脉冲结束后发生的，涉及金属薄层的破碎（没有明显的温度过高的热损伤迹象），而不是高温引起的熔体损伤。在本文中，通过使用速度分量代替运动动力学方程中的位移分量，并采用交错网格，我们开发了一种有限差分方法来研究暴露于超短脉冲激光的二维薄膜中的热变形，其中薄膜分别是具有完美界面热接触和不完美界面热接触的单层薄膜和双层薄膜。该方法基于抛物线式两步传热方程式获得。它解释了晶格温度和应变率之间的耦合效应，以及动量传递中的热电子冲击效应。发达的方法使我们避免了溶液中的非物理振荡。迄今为止，在感兴趣的问题中，这种振荡已成为大多数数值方法的固有特征。基于物理的，无数值振荡的方法对热超短脉冲激光加热的金属薄膜进行热分析的方法，在这一实际重要的研究领域中代表着具有挑战性的工具。通过研究（1）单层金薄膜，（2）在界面处具有完美热接触的双层金和铬薄膜以及（3）中的温度升高和变形来测试该方法的适用性。界面处接触不良的双层金和铬薄膜。结果表明，溶液中没有非物理振荡，该方法是有前途的。

著录项

  • 作者

    Wang, Haojie.;

  • 作者单位

    Louisiana Tech University.;

  • 授予单位 Louisiana Tech University.;
  • 学科 Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 133 p.
  • 总页数 133
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 工程材料学;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号